Mechanical reciprocator

ABSTRACT

A reciprocating member is alternately engaged to be driven first in one direction by an arcuate rack and in the opposite direction by a pinion both of which are power actuated from a common source.

United States Patent Prosser MECHANICAL RECIPROCATOR Inventor: David G. Proser, Mequon, Wis. Assignee: Autotrol Corporation, Milwaukee, Wis.

Filed: Sept. 2, 1970 Appl. No.: 69,058

Related 0.8. Application Data Division of Ser. No. 818,763, April 23, 1969, Pat. No. 3,574,330.

US. Cl ..74/32 Int. Cl .f. ..Fl6h 19/04 Field of Search ..74/29, 30, 31, 32, 33, 34,

[451 June 27, 1972 [56] References Cited UNITED STATES PATENTS 1,061,753 5/1913 Kirchofi ..74/30 2,494,706 H1950 Happel ..74/30 X 513,554 l/l894 Blake ..74/3l Primary Examiner-william F. ODea Assistant Examiner-P. 0. Ferguson Attorney-Thomas O. Kloehn and Thomas E. Ehrmann ABSTRACT A reciprocating member is alternately engaged to be driven first in one direction by an arcuate rack and in the opposite direction by a pinion both of which are power actuated from a common source.

4 Claims, 5 Drawing figures PATENTEIJJum 19. 2

SHEET 20F 2 INVENTOR DAVID G. PROSSER ATTORNEY MECHANICAL RECIPROCA'IOR CROSS-REFERENCE TO RELATED APPLICATIONS This is a division of application, Ser. No. 818,763, filed Apr. 23, 1969 now U.S. Pat. No. 3,574,330.

BACKGROUND OF THE INVENTION Generally a reciprocate member is usually actuated by means of a reversible type power system which requires that the power system be informed as to the completion of the travel in each direction. This requires mechanism not particularly suitable for congested areas where limited space is available for the mechanism. The present invention provides a compact, feasible and practical mechanism for utilizing a single available power source for actuating a reciprocal member in each direction. In one direction the drive in onedirection is effected with maximum force with the drive in the second direction being effected with relative light force and at a high speed. This system, while effective, has a number of disadvantages. lt is'easy to misjudge the time when regeneration is needed and if the period between regenerations is too long, the customer will get soft water only part of the time and will be dissatisfied. To avoid that result, the periodic regeneration of the resin bed, based solely on time, necessitates excessive amounts of salt, because a large safety factor must be calculated to ensure that the bed is never completely exhausted, and then it tends to become burdensome to the customer to maintain an adequate salt supply for the frequent regenerations. If, for any reason, the customer suddenly stops using water, as occurs for example in residential installations when the residents leave for extended vacations, the regeneration of the bed,'though unnecessary, proceeds at the pre-set intervals. Finally, it is not unusual for the volume of water used and water hardness to fluctuate widely, requiring repeated service calls to reset the frequency of regeneration.

It is known that some ion exchangers, if washed with water,

will reflect the ion content of the water with radical changes involume. This phenomena is explained and disclosed in US. Pat. No. 2,810,692, which issued on Oct. 22, 1957. It has remained for the present invention to provide a feasible, workable and practical means for utilizing that phenomenon to determine the need for and to effect regeneration of the softener ion exchanger automatically only when the softener ion exchanger becomes exhausted. Thus the present invention obviates the disadvantages of the time controlled regeneration systems, to enhance the practical success of water softener installations, particularly installations which are not attended by trained and skilled personnel.

SUMMARY OF THE INVENTION The invention relates to a reciprocator including a drive gear that has a tubular hub with an arcuate rack on an end spaced axially from the drive gear and that is driven through a gear train by a power source, a return gear that is mounted concentrically with said drive gear and has a hub with a pinion on its end projecting through said tubular hub of said drive gear and that is driven by said power source through a second gear train to rotate in an opposite direction from said drive gear, and a reciprocating rack mounted to be alternately drivingly engaged by said arcuate rack on said drive gear hub and said pinion on said return gear hub.

The reciprocator described above can impart maximum force to the reciprocating rack in the drive direction and a high speed return to the reciprocating rack at the end of the drive stroke. It is a highly flexible reciprocator mechanism that can utilize the power source with maximum efficiency to produce a controlled reciprocating motion in an indefinite range of speed and power characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a view in front elevation of a sensor control embodying the present invention with portions broken away to reveal internal functioning structure,

FIG. 2 is an exploded view in perspective of an output gear assembly from the sensor control shown in FIG. I,

FIG. 3 is an exploded view in perspective of the output gear assembly shown in FIGS. land 2 as viewed from the bottom of FIG. 2,

FIG. 3 is an exploded diagrammatic view of the gear trains and assemblies in the sensor shown in FIG. 1, and

FIG. 5 is an exploded view of the rotary control assembly employed in the sensor control shown in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention has been found to be particularly useful in a sensor control for a water softener system. Advantages of the present invention will be more fully appreciated as its operation in sensor control is understood.

As can be seen in FIG. 1, the mechanism of the sensor con-' trol is enclosed in a rectangular housing 1, the cover (not shown) of which is removed to reveal the mechanism. The rectangular housing 1 would be mounted on top of a water softener tank on the end of a valve control assembly such as is shown in my co-pending application, Ser. No. 739,539, filed June 24, 1968, now US. Pat. No. 3,580,615, and entitled Softener Control Assembly", it being the function of this mechanism to transmit driving force to the mechanism shown in that application for operating valves that control the flow of this water to be treated and of the regeneration fluid. Mounted to the bottom of the housing 1 by means of screws (not shown) is a sample sensing chamber 2, which is shown in section to reveal its interior, and which contains an ion sensitive resin 20 which shrinks when wetted with hard water.

The sample sensing chamber 2 is a hollow, rectangular shaped object made of a section of plastic rectangular tubing forming the vertical sidewalls and molded plastic top and bottom members 21 and 23, respectively, which are assembled together by the mounting screws (now shown) that extend vertically through the corners of those three pieces and into the housing 1. A flexible sampling tube 3 is suspended by a threaded sleeve 4 on a tubular fitting 4a that protrudes from the bottom of the sample sensing chamber 2, and the sampling tube 3 passes through an adjustable gripping seal5 that is screw mounted in an upper wall 6 of a water softener tank. A weighted intake nozzle 10 is fastened on the end of the sampling tube 3 that is suspended in a bed of softener ion exchanger (not shown) inside the softener tank. An exhaust tubing 7 is fastened by a threaded sleeve 8 to a tubular fitting 8a that protrudes from the bottom of the sample sensing chamber 2 on the opposite side from the sampling tube 3.

A valve assembly 11 normally closes the mouth of the sampling tube 3 and has a valve stem 12 that extends upward out of the sample sensing chamber 2. Inside the sensing chamber 2 a vertical tube 13 which is vented with a plurality of vertically spaced transverse slots or openings houses a needle 14 on the 7 end of the valve stem 12. A pair of O-ring seals 15 and 16 are fixed in annular seats at opposite ends of the tube 13. The valve stem 12 is sealed through the upper O-ring l6, and the needle 14 is inserted snugly through the lower O-ring to close the valve assembly 11. To open the valve assembly 11, the valve stem 12 is lified, withdrawing the needle 14 from the lower O-ring 16. A vertical drain tube 24 that is vented with a plurality of transverse slots or openings extends from the inner mouth of the tubular fitting 8a which opens outwardly into the exhaust tubing 7, to the ceiling of the interior of the chamber 2. Thus, fluids introduced to the chamber 2 through the valve assembly 11 will tend to flow horizontally across the chamber 2 into the vertical drain tube 24 and then down into and out through the exhaust tubing 7.

A flexible diaphragm 17 extends across and seals the top of the interior of the sample sensing chamber 2. The diaphragm 17 is a soft, rubber membrane that is sealed about its peripheral edges between the tops of the lateral walls and the top piece 21 of the sample sensing chamber 2 and it passes beneath a mechanical sensor in the form of a plunger 18, to which it is screw fastened. A compression spring 19 urges the plunger 18 downwardly. One end of the compressing spring 19 bears against a spring seat 20 in the plunger 18, and the other end of which bears against the top 21 of the sample sensing chamber 2. A plug 22 is screw fitted in an opening through the floor piece 23 of the sample sensing chamber 2 so that the sample sensing chamber 2 may be opened without dismantling it.

The mechanism shown in the rectangular housing 1 in FIG. 1 is most easily describedusing the exploded diagram in FIG. 4. An electric low speed 25 is mounted on the outside surface (not shown) on a back wall 26 of the rectangular housing 1 to provide a power source for the entire mechanism of the sensor control, and its drive shaft 27 projects through a bearing (not shown) in the back wall 26 of the rectangular housing 1. The drive shaft 27 has a main drive pinion 28 mounted on it adjacent the inside surface of the back wall 26, and the shaft 27, and pinion 28 are continuously driven by the motor 25. The main drive pinion 28 simultaneously drives four gear trains 29, 30, 31 and 32, which share some common elements, though each train 29-32, performs a specific end function distinct from the others.

The sampling gear train 29 has a spur gear 33 engaged with the main drive pinion 28 with a reduction pinion 34 formed on its hub. The reduction pinion 34 drives a second spur gear 35 that has a reduction pinion 36 on its hub, which simultaneously drives two spur gears 37 and 38, the latter gear 38 operating only in the sampling return gear train 30. The spur gear 37 that is driven by the reduction pinion 36, has a reduction pinion 39 onits hub, and this reduction pinion 39 engages a drive gear segment 40 that forms a part of a rotary control assembly 41, which is illustrated in an exploded view in FIG. 5.

The sampling return gear train 30 shares the spur gears 33 and and their respective reduction pinions 34 and 36 with the sample gear train 29, and has in addition the mentioned spur gear 38 with an extended hub 42 that has a pinion 43 formed on top of it. The extended hub 42 of the return spur gear 38 passes through the hollow center of an annular hub 44 that is formed on the drive gear segment 40. The sampling return spur gear 38 is rotatably mounted on the back wall 26 of the rectangular housing 1 and it rotatably supports the drive gear segment on an annular collar 45 that is formed on the upper surface of the spur gear 38.

The rotary control assembly 41 is, among other things, a unique form of rotary mechanical amplifier. In addition to the drive segment 40, referred to above, the rotary control assembly 41 includes a trigger gear segment 46 that has for a hub an annular ring 47,.which fits rotatably about the hub 44 of the drive gear segment 40. The drive segment 40 is a circular gear segment 40, the ends of which are separated by a short gap 48, and the trigger segment 48 is provided with a shorter gear segment 46 that has the same pitch diameter and tooth configuration as the drive gear segment 40. A circular bias spring 49 fits around the annular ring 47 of the trigger segment 46 and has one end hooked about a hook 50 projecting from the drive segment 40 and its other end hooked on a hook 50a projecting from a trigger segment 46. A pair of limit arms 51 project radially from the hub 44 of the drive segment 40 through slots 1 13 in the tubular hub 47 of the trigger segment 46 to limit the rotational movement of the trigger segment 46 with respect to the drive segment 40, and the arms, incidentally, also restrain the bias spring 49 axially to hold it in place. The assembly utilizes the functional elements mutually to restrain each other so that no additional screws, rivets or other assembly members are needed. The tension of the bias spring 49 is such and the hook 50 on the drive segment 40 and hook 50a on the trigger segment 46 are so located that the trigger segment 46 is normally biased to a position immediately adjacent to one end of the gap 48 between the ends of the drive segment 40. The trigger segment 46 has a trigger member 52 projecting horizontally, as viewed in FIG. 1, and a radial trigger member 53 extending outwardly from it. When the drive segment 40 is at rest with the pinion 39 turning freely in the gap 48 between its ends, either the trigger member 52, or the trigger member 53 may be engaged to overcome the bias spring 49 and rotate the trigger segment 46 into the gap 48 between the ends of the drive segment 40.

The slots 113 define the amount of movement of the trigger segment 46 relative to the drive segment 40, and when one of the triggers 52 or 53 moves the trigger segment 46, it moves the trigger segment 46 to the limit of its relative motion. Thus the trigger segment 46 has two positions relative to the drive segment 40, one at each end of its relative motion, and in each it is in alignment with the drive segment 40. When the trigger segment 46 is in a position wherein it spans the gap 48, it engages the reduction pinion 39 on the spur gear 37, which will rotate the drive segment 40 by means of the trigger segment 46 until the reduction pinion 39 is in direct driving engagement with the drive segment 40. Then the trigger segment 46 can be released and rotated back to its normal position by the bias spring 49. A relief slot 116 is cut in the trigger gear segment 46 to allow the trigger segment 46 to flex. Since the trigger segment is made of a resilient plastic, it can thus be formed to flex under strain. Hence, if the trigger segment 46 is not in perfect alignment with the drive gear segment 40, preventing the drive pinion 39 from meshing immediately with it, the gear teeth will not be damaged. This permits much larger tolerances in the manufacturing specifications with resulting reductions in costs.

A semi-circular collar 54 extends axially from the top end of the hub 44 on the drive segment 40 and on one end of the collar 54 an arcuate gear rack 55 is formed. A linearly reciprocably slidable cam member 56 is located adjacent to the collar 54 and it has a linear gear rack 57 on its upper surface that can be engaged by the arcuate gear rack 55 on the collar 54 as the collar 54 rotates with the drive segment 40. When the arcuate gear rack 55 engages the linear gear rack 57 on the cam member 56, it drives the cam member 56 to the left, as viewed in FIG. 1, and the linear gear rack 57 is held into engagement with the arcuate gear rack 55 by an extension spring 58, one end of which is fastened to the end of the cam member 56 and the other'end of which is anchored to a post 59 projecting from the back wall 26 of the housing 1. After the arcuate gear rack 55 has been rotated out of engagement with the linear gear rack 57 on the cam member 56, the linear gear rack 57 rides on the smooth surface of the collar 54 until the end of the collar 54 is rotated past it. When the collar 54 thus releases the linear gear rack 57, the rack 57 is pulled into engagement with the counter rotating pinion 43 on the top of the hub 42 of the return spur gear 38, which drives the cam member 56 back to its extreme position on the right.

The rotating arcuate gear rack 55 with the concentric, counter rotating return pinion 43, both being driven from a common source through separate gear trains 29 and 30, present a highly flexible mechanism for effecting reciprocating motion with maximum efficiency. In this embodiment this mechanism is used primarily to effect a controlled return of the cam member 56, in lieu of utilizing a spring return or some other such additional force. However, the mechanism can provide, for example, tremendous mechanical force advantage in one direction with a very high speed, light force return. This would allow maximum utilization of energy during a working stroke with minimum loss on the return.

The output gear train 31 shares with the timing gear train 32 a spur gear 60, which is driven by the main drive pinion 28. The spur gear 60 has a reduction pinion 61 on its hub, and the reduction pinion 61 drives a second spur gear 62 which has a reduction pinion 63 on its hub. A circular output gear segment 64 is rotatably mounted in the housing 1, and it is engaged by the reduction pinion 63. The output segment 64 is part of a rotary output assembly 65 that is illustrated in exploded view in FIGS. 2 and 3.

The output gear segment 64 has an extended, hollow tubular hub 66 projecting axially out of the rectangular housing 1 with an indicator arrow 67 formed across its top surface and knurled grip portion 68 about its top end. The hollow hub 66 fits rotatably about a portion of a cylindrical journal bearing 69 that is anchored to the back wall 26 of the housing 1 and that projects from the back wall 26 into the housing 1. The journal bearing 69 rotatably mounts-an output shaft 105. A compression spring 70 is seated in a spring seat 106 in the drive shaft 105 and bears against the inside of the hub 66, which is restrained in its axialmovement by the inside of a front wall (not shown) of the rectangular housing 1. The compression spring 70 tends to hold the output segment 64 into engagement with the reduction pinion 63 formed on the hub of the spur gear 62, so that the hub 66 of the output segment 64 may be manually depressed to release the output segment 64 which. then may be manually rotatably adjusted free of engagement .with the spur gear 62. Rectangular keys 106 and 107 extend radially from opposite sides of the output shaft 105 to slide in grooves 108 and 109 formed on the inside of the hub 66. Thus the rotational movement of the output gear segment 64 is transmitted to the output shaft 105, which conveys sembly 41. Hence, what has been said of the operation and capabilities of the control assembly 41 applies as well to the corresponding structure in the output assembly 65. The output segment 64 is a circular gear segment 64 with a small gap 71 between its ends. A trigger gear segment 72, which also is a circle segment 72 and which has the same pitch diameter and gear configuration as the output segment 64, has an annular ring 73 for a hub that forms a rotating fit about the hub 66 on the output segment 64. A circular bias spring 74 fits about the annular ring 73, and one of its ends engages a hook 75 on the trigger segment 72-and the other end is anchored to a hook 75a on the output segment 64. The bias spring 74'is restrained beneath a pair of limit arms 76 that radiate from the hub '66'of the output segment 64 through slots 77 in the annular ring 73 above the trigger segment 72, and the limit arms 76 serve to limit the amount of relative rotational movement of the trigger segment 72 with respect to the output segment 64. A vertical trigger 78 projects from the trigger segment 72 so that it may be engaged by some external device torotate the trigger seg ment 72 relative to the output segment 64 against the bias spring 74. Normally the trigger segment 72 is held adjacent to one end of the gap 71 that is provided between the ends of the gear segment 64, but when the trigger segment 72 is actuated by engaging the vertical trigger 78, the trigger segment 72 rotates into a position above the gap 71 so that the reduction pinion 63 can mesh with the trigger segment 72 and, through the trigger segment 72, drive the output segment 64 until it meshes directly with the output gear segment 64. When the pinion 63 is enmeshed with the output segment 64 the trigger segment 72 is released to return to its normal position. The trigger segment 72 is provided with a relief slot 115 that corresponds in structure and function to the relief slot 116 in the trigger gear segment 46 of the control assembly 41.

The sensing plunger 18 in the sample sensing chamber 2 shown in FIG. 1 has a rod 79 extending from it and projecting out of the sample sensing chamber 2 upwardly into the housing 1. An arm 80 extends from the end of the rod 79 and has a latch 81 on its upper end that is positioned adjacent to the tubular ring 73 with the latch 81 being disposed above the trigger 78 of the output trigger gear segment 72, as viewed in FIG. 1. Thus the latch 81 will reciprocate with the plunger 18 to move into and out of the path of the trigger 78 on the trigger gear segment 72. A cam follower 82 projects outwardly from the arm 80 on the rod 79 of the plunger 18 to ride on a cam surface 83 over the top of the cam member 56. The left end of the cam surface 83 is relatively low but it rises sharply to the right before leveling off, so that as the cam member 56 is driven to the left the plunger 18 is hoisted to the top of its stroke in the sample sensing chamber 2 and the latch 81 is positioned above the trigger 78 on the trigger gear segment 72. When the cam member 56 moves to its sensing position at the extreme right, the cam surface 83 releases the cam follower 82 and the plunger 18, which is then driven downward by the compression spring 19. If the movement of the plunger 18 in the chamber 2 is not obstructed, the latch 81 will engage the trigger 78 and pull the trigger gear segment 72 against the bias spring 74 into a position wherein it spans the gap 71 between the ends of the output gear segment 64 to engage the reduction pinion 63.

The last gear train to be described is the timing gear train 32. The timing gear train 32, as was mentioned, shares the spur gear 60 and reduction pinion 61 withthe output gear train 31, and thereduction pinion 61 drives a first spur gear 84. A reduction pinion 85 on the hub of the first spur gear 84 engages a second spur gear 86, which also has a reduction pinion 87. The reduction pinion 87 on the second spur gear 86 engages a third spur gear 88 to drive a timing gear 89 through a reduction pinion 90 on the hub of the third spur gear 88. The timing gear 89 makes one revolution each 24 hours, and it is mounted to be manually set to the time the mechanism is put into operation. An annular collar 91 is mounted on the under side of the timing gear 89, and on one end of the annular collar 91 an extension 92 projects approximately radially outwardly toward the periphery of the timing gear 89. This radial extension 92 of the annular collar 91 is shaped and positioned so that it can engage the trigger 52 projecting from the trigger segment 46 in the control assembly 41 to drive the trigger segment 46 so that the gear segment thereof is positioned across from the gap 48 that is provided between the ends of the drive gear segment 40. The resulting rotation of the drive segment 40, as hasbeen described, drives the cam member 56, which controls the sensing and sampling of the water being treated in the softener tank 6.

The sampling valve assembly 11 has a rectangular extension portion 93 on the valve stem 12 that has a guide slot 94 in it, through which a guide post 110 projecting from the back wall 26 of the housing 1 extends to guide its reciprocating travel. On the end of the extension 93 of the valve stem 12 a cam follower 95 projects outwardly through a slotted cam groove 96 in the cam member 56. .The lefi two-thirds of the slotted cam groove 96 is horizontal, but in the right one-third,'the cam groove 96 rises sharply to a brief plateau at the right end, so that as the'cam member 56 moves to the left, the valve stem l2'and needle 14 are raised rapidly during the last third of its travel to open the sampling valve assembly 11. This allows a sample of fluid from the sampling tube 3 to enter the sample sensing chamber 2 while the plunger 18 is lifted to its highest position.

To set forth the operating cycle in logical sequence, start with the drive gear 40 of the rotary control assembly 41 rotated to a position where the pinion 39 is turning freely in the gap 48 between the ends of the drive segment 40 and the drive segment 40 is stationary. Also begin with the output segment 64 rotated to a stationary position where the pinion 63 is turning freely in the gap 71 between the ends of the output gear segment 64. Finally, assume that the trigger gear segment 46 in the rotary control assembly 41 and the trigger segment 72 in the rotary output assembly 65 are resting in their normal positions.

As the drive motor 25 drives the four reduction gear trains 29, 30, 31 and 32, only one of the reduction gear trains, the timing gear train 32, is performing a function at all times and it is rotating the timing gear 89 at a rate that provides one complete revolution every 24 hours. Most of the time the other three gear trains 29-31, viewed in terms of an ultimate accomplishment, are simply idling..Assume that the collar 91 with its radial extension 92 on the timing gear 89 is positioned to initiate a sampling at 2 o'clock in the morning. For purposes of description, assume that the operation begins moments be fore 2:00 A. M. The radial extension 92 of the collar 91 would be seen to approach engagement with the trigger 52 on the trigger gear segment 46 of the rotary control assembly 41. As the timing gear 89 continues to move past 2:00 A. M., the radial extension 92 of the collar 91 engages the trigger 52 and drives the trigger gear segment 46 into the gap 48 between the ends of the drive segment 40 where it is engaged by the spinning pinion 39. When the control drive pinion 39 drives the trigger segment 46, the trigger segment 46 pulls the drive segment 40 into engagement with the pinion 39, which then directly drives the drive segment 40 rotating it until the pinion 39 again reaches the gap 48. As the drive segment 40 rotates, the arcuate gear segment 55 on the collar 54 projecting from the top of the hub 44 of the drive segment 40, which was already engaged with the rack 57 on the top of the cam member 56, drives the cam member 56 to the left in the drawing, and then rotates past engagement with the linear cam rack 57 so that the cam rack 57 rests on the collar 54.

With the cam member 56 driven to its left most position, the cam follower 95 on the extension 93 of the valve stem 12 has followed the cam groove 96 to its highest point, lifting the valve stem 12 and the needle valve 14 to open the valve 11 to allow a sample of water from the softener tank 6 to flow up through the sampling tube 3 into the tube 13 in the sample sensing chamber 2. The water simple is sprayed out of the tube 13 through its vertically spaced openings and it thoroughly washes and agitates the sensing ion exchanger 2a as it flows across the chamber 2 and enters the drain tube 24 through its many vertically spaced openings to flow out of the chamber 2. After the collar 54 has rotated past the linear rack 57, the meshing spring 58 draws the rack 57 into engagement with the cam return pinion 43, which, rotating in the opposite direction from the drive segment 40 of the control assembly 41, drives the cam member 56 back to the right end of its stroke.

This return of the cam member 56 to the right end of its stroke forces the cam follower 95 on the extension 93 of the valve stem 12 downward, driving the end of the needle valve 14 through the O-ring 15 to close the sample intake valve assembly 1 1. As the cam member 56 reaches the right end of its reciprocating travel, the cam surface 83 drops off sharply, releasing the cam follower 82 on the shaft 80 of the sensing plunger 18, allowing the compression spring 19 to drive the plunger 18 down against the resin 2a within the sampling chamber 2. If the sample of water from the softener tank 6 that wets the cation exchange resin 2a in the chamber 2, is soft, the cation exchange resin 2a will manifest its normal maximum volume and the travel of the plunger 18 into the sensing chamber 2 will be obstructed and stopped. However, if the water sample is hard, the cation exchange resin 2a will shrink allowing the plunger 18 to drop under the impetus of the compression spring 19 to the bottom of its stroke.

When the output segment 64 is in the position specified so that its drive pinion 63 is rotating freely in the gap 71 between the ends of the output gear segment 64, the horizontally extending trigger 78 on the trigger segment 72 is in the position shown in H6. 1 immediately beneath the latch 81. Hence, when the plunger 18 is allowed by the shrunken resin 2a in the chamber 2 to drop down, the latch 81 engages the trigger 78 pulling it downwardly with the force of the compression spring 19 to drive the trigger segment 72 into its actuated position in the gap 71 between the ends of the output gear segment 64 so that it can engage the output drive pinion 63. The output drive pinion 63 then begins to rotate the output segment 64, first through the trigger segment 72 and then directly as it comes in mesh with the output gear segment 64.

Meanwhile, the drive segment 40 of the control assembly 41 has continued its rotation under the impetus of the pinion 39, until it brings the arcuate rack 55 back into engagement with the linear rack 57 on the cam member 56 and drives the cam member 56 to the left sufficiently to cause the cam follower 82 to ride upwardly on the output cam surface 83. The movement of the follower 82 on the cam surface 83 lifts the plunger 18 from the top of the cation exchange resin 2a in the chamber 2. Thus as soon as the cam member 56 has been driven sufficiently far to the left to thus raise the plunger 18, the drive segment 40 of the control assembly 41 completes one rotation with the pinion 39 once again turning freely in the gap 48 between the ends of the drive segment 40.

While the drive segment 40 of the control assembly 41 is returning the cam 56 to its normal, central position to hold the plunger 18 off of the sensing ion exchanger 2a, the output segment 64 on the output gear assembly 65 is rotating, transmitting the drive force of the motor 25 to the control mechanism of the mentioned co-pending application, Ser. No. 739,539, filed on June 24, 1968, and entitled Softener Control Assembly which closes the valves for the hard water flow, and opens the valve to initiate the flow of brine through the softener ion exchanger (not shown) to regenerate it. By the time the output segment 64 has been rotated approximately degrees, the drive segment 40 has completed its rotation and its trigger member 53 is projecting radially over the top of the output segment 64. At this point in time, a horizontally extending actuator 114 projecting outwardly from the output segment 64, as viewed in FIG. 1, strikes the radially extending trigger member 53 on the trigger segment 46 of the control assembly 41 the output segment 64 continues to rotate, the actuator 114 drives the trigger segment 46 of the control assembly 41 into its actuated position across the gap 48 between the ends of the drive segment 40 to engage the rotating control drive pinion 39, which then begins to drive the drive segment 40 through a second rotation.

As the drive segment 40 rotates, the arcuate rack 55 on the collar 54 projecting from the hub 44, which is in engagement with the cam rack 57 on the cam member 58, drives the cam member 56 to its left end position, where it is held by the collar 54 after the arcuate rack 55 has rotated past engagement with the cam rack 57. When the cam member 56 is in that extreme left most position of its reciprocating movement, the sampling intake valve assembly 11 is opened again and the plunger 18 is lifted to the top of its stroke so that it can exert no pressure on the cation exchange resin 2a within the sample sensing chamber 2.

The cam member 56, after opening the valve 11 returns to the opposite extreme of its reciprocating movement, so that it is'to the far right in the drawing. The drive segment 40 of the control mechanism 41 continues rotating until the arcuate rack 55 once again engages the linear cam rack 57 on the cam member 56 and drives the cam member 56 from the right hand extreme of its reciprocating movement back to its normal central position. At that point, the gap 48 between the ends of the drive segment 40 again reaches the control drive pinion 39 to halt the rotation of the drive segment 40, thus ending the entire operating cycle and holding the control mechanism 41 in its normal position until the timing gear 89 initiates the next sampling.

Viewed in a more general context, the control segment 40 and the output segment 64 become power transmitting gear segments 40 and 64 and the respective trigger segments 46 and 72 are responsive to mechanical input signals to initiate transmission of power by the power transmitting segments 40 and 64. For the control assembly 41, the input signal is a timing pulse periodically emitted by the timing gear 89 and the output segment 64. For the output assembly 65, the input signal is an error feedback signal from the plunger 18 indicating that the treated water at a preset level in the softener bed does not manifest the desired condition. Both input signals are or may be relatively weak and the output power transmitting to the output means, i.e., the output shaft and the cam member 56, by the power transmitting segments is, or may be, very great. The cam member 56 also normally holds the plunger 18 out of engagement with the sensing resin 20 so that the sensing ion exchanger 2a can seek its proper volume and will not be damaged.

The embodiment just described represents the best mode presently contemplated by the inventor for carrying out this invention. However, other embodiments will be developed to meet the needs of other systems and still more embodiments are possible that may not be practiced. Hence, the invention is not to be confused with a specific embodiment of it. The invention itself is particularly pointed out in the claims that follow.

I claim:

I. A mechanical reciprocator comprising the combination a drive gear rotated by a power source, and having an axially elongated hub with an arcuate rack on it;

a return gear rotated by said power source in a direction opposite to said drive gear, and having an elongated hub with a pinion on it;

said drive gear and said return gear being driven independently of one another and said arcuate rack and said pinion being free from meshing engagement with one another;

said axially elongated hub on said drive gear and said elongated hub on said return gear being concentrically mounted together; and a reciprocating member alternately in driving engagement with said arcuate rack and said pinion. 2. A mechanical reciprocator as set forth in claim 1 wherein said elongated hub on said drive gear is tubular and said arcuate rack extending part way about its end; and said elongated hub on said return gear is rotatably mounted inside said tubular elongated hub on said drive gear and has said pinion on its end adjacent to said arcuate rack. 3. A mechanical reciprocator as set forth in claim 1 wherein said reciprocating member has a linear rack on it that al ternately engages said arcuate rack and said pinion and said reciprocating member is mounted for linear reciprocating movement. 4. A mechanical reciprocator as set forth in claim 1 wherein said arcuate rack includes a smooth collar partially surrounding said pinion, 

1. A mechanical reciprocator comprising the combination of a drive gear rotated by a power source, and having an axially elongated hub with an arcuate rack on it; a return gear rotated by said power source in a direction opposite to said drive gear, and having an elongated hub with a pinion on it; said drive gear and said return gear being driven independently of one another and said arcuate rack and said pinion being free from meshing engagement with one another; said axially elongated hub on said drive gear and said elongated hub on said return gear being concentrically mounted together; and a reciprocating member alternately in driving engagement with said arcuate rack and said pinion.
 2. A mechanical reciProcator as set forth in claim 1 wherein said elongated hub on said drive gear is tubular and said arcuate rack extending part way about its end; and said elongated hub on said return gear is rotatably mounted inside said tubular elongated hub on said drive gear and has said pinion on its end adjacent to said arcuate rack.
 3. A mechanical reciprocator as set forth in claim 1 wherein said reciprocating member has a linear rack on it that alternately engages said arcuate rack and said pinion and said reciprocating member is mounted for linear reciprocating movement.
 4. A mechanical reciprocator as set forth in claim 1 wherein said arcuate rack includes a smooth collar partially surrounding said pinion. 